supercall: Add SUPERCALL_SU_GET_SAFEMODE

kernel/patch/android/userd.c

@@ -383,8 +383,6 @@ static void before_input_handle_event(hook_fargs4_t *args, void *udata)
         if (volumedown_pressed_count == 3) {
             log_boot("entering safemode ...");
             android_is_safe_mode = 1;
-            struct file *filp = filp_open(SAFE_MODE_FLAG_FILE, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-            if (filp && !IS_ERR(filp)) filp_close(filp, 0);
         }
     }
 }

kernel/patch/common/supercall.c

@@ -199,6 +199,16 @@ static long call_su_allow_uid_nums()
     return su_allow_uid_nums();
 }
 
+#ifdef ANDROID
+extern int android_is_safe_mode;
+static long call_su_get_safemode()
+{
+    int result = android_is_safe_mode;
+    logkfd("[call_su_get_safemode] %d\n", result);
+    return result;
+}
+#endif
+
 static long call_su_list_allow_uid(uid_t *__user uids, int num)
 {
     return su_allow_uids(1, uids, num);
@@ -276,6 +286,10 @@ static long supercall(int is_key_auth, long cmd, long arg1, long arg2, long arg3
         return call_su_get_allow_sctx((char *__user)arg1, (int)arg2);
     case SUPERCALL_SU_SET_ALLOW_SCTX:
         return call_su_set_allow_sctx((char *__user)arg1);
+#ifdef ANDROID
+    case SUPERCALL_SU_GET_SAFEMODE:
+        return call_su_get_safemode();
+#endif
     default:
         break;
     }

kernel/patch/include/uapi/scdefs.h

@@ -95,6 +95,7 @@ struct su_profile
 #define SUPERCALL_SU_SET_ALLOW_SCTX 0x1106
 #define SUPERCALL_SU_GET_PATH 0x1110
 #define SUPERCALL_SU_RESET_PATH 0x1111
+#define SUPERCALL_SU_GET_SAFEMODE 0x1112
 
 #define SUPERCALL_MAX 0x1200
 

user/supercall.h

@@ -416,6 +416,18 @@ static inline long sc_skey_root_enable(const char *key, bool enable)
     return ret;
 }
 
+/**
+ * @brief Get whether in safe mode
+ *
+ * @param key
+ * @return long
+ */
+static inline long sc_su_get_safemode(const char *key)
+{
+    if (!key || !key[0]) return -EINVAL;
+    return syscall(__NR_supercall, key, compact_cmd(key, SUPERCALL_SU_GET_SAFEMODE));
+}
+
 // todo
 static inline long sc_pid_virt_to_phys(const char *key, pid_t pid, unsigned long vaddr)
 {